Moult papers:

references, abstracts and comments. Where there is no abstract, an abstract has been written, where abstracts are too long they have been abridged, where the English is poor it has been improved. Abstracts/summaries in languages other than English have been translated into English, some extremely bad abstracts (and even headings) from Ringing & Migration have been corrected when called for. The comment is personal, it points out errors and possible follow-ups, it is begun: CP:

ascending (ascendent, ascendant) primary moult: begins with the outermost primary.
descending (descendent, descendant) primary moult: begins with the innermost primary.
distal primary: the most distant ones from the body
prebasic moult = postnuptial moult
proximal primary: the ones closest to the body
transilient mode: from the last moulted remige there is a forward or backward jump, omitting one or several intermediary remiges.
dorsal: on the back side
ventral: on the belly side

A, B, C, D, E, F

Ainley, D. G., T. J. Lewis & S. Morrell (1976): Moult in Leach's and Ashy Storm-petrels. Wilson Bull. 88: 76 - 95.

Molt in Ashy Storm-petrels proceeds rather regularly from one phase to another; when one phase reaches peak intensity the next begins. In adults, body molt starts at about egg-hatching, 40 days later rectrices begin their molt, 30 days after that primaries begin molt, followed by secondaries almost immediately. Most Ashy Storm-petrels have half-completed tail molt and are molting the first 2 or 3 primaries when their chick fledges. They are still molting the last 2 or 3 primaries on their first visits to the island in the following nesting cycle. The total time required for molt averages 257 days. Molt in Leach's Storm-petrels proceeds in the same order but the intervals between start of the various phases differ. Tail molt begins only 20 days after start of body molt, 50 days later primaries begin molt, and about 30 days after that molt in the secondaries begins. When the chick fledges, parents have almost completed tail molt but usually have not begun wing molt. Most Leach's Storm-petrels complete molt before visiting the island in the following breeding cycle. Total time required for molt averages 274 days. The sequences of feather replacement and the rates of growth in individual feathers are described.
Immatures begin molt earlier in the year than adults, starting about the time the latter are laying and incubating eggs.
Little overlap occurs between molt and migration, and between primary molt and breeding in the Leach's compared to extensive overlap between these activities in the Ashy Storm-petrel. The different molt regimes correspond to the overall divergence in life styles of the 2 species, Leach's being a long-ranging, migratory species of subtropical open-ocean waters and the Ashy being a short-ranging, sedentary species inhabiting subarctic coastal waters. Molt in the Leach's is similar in its timing and degree of overlap with other activities to the British Storm-petrel; but the molt regime in theAshy is unique among storm-petrels so far studied.

Anderson, K. R. (1973): The biometrics, moult and recoveries of British-ringed Ruff. Wader Study Group Bull. 11: 5 - 14.

Appleton, G. F. & C. D. T. Minton (1978): The primary moult of the Lapwing. Bird Study 25: 253 - 256.

From moult data gathered mainly in Staffordshire, the duration of primary moult by individual Lapwings is estimated at about 114 days, the main period extending from early June to late September. This is longer than was claimed by a previous analysis using another technique,(...)

Ashmole, N. P. (1962): The Black Noddy Anous tenuirostris on Ascension Island. Part 1. General Biology. Ibis 103b: 235 - 273.

Ashmole, N. P. (1963): Molt and breeding in populations of the Sooty Tern Sterna fuscata. Postilla 76: 1 - 18.

Ashmole, N. P. (1968): Breeding and molt in the White Tern Gygis alba on Christmas Island, Pacific Ocean. Condor 70: 35 - 55.

Aymí, R. & J. Jaume. (1992): Muda interrompuda en una Cuereta groga Motacilla flava. Butll. GCA 9: 11 - 12.

During a ringing campaign of Yellow Wagtails, 2438 individuals were handled at the Ebro Delta (NE Spain) in September 1992. On 27th September 1992 an adult Yellow Wagtail with interrupted moult was trapped. The bird had renewed all its plumage during the postnuptial moult, with the exception of the two innermost secondaries, two to six feathers in the median and less coverts of each wing and the smaller feather of the alula in the right wing. This is the first record of interrupted moult in the species.


Aymí, R. (1997): Additional cases of interrupted moult in the Yellow Wagtail Motacilla flava. Ring. & Migr. 18: 33 - 34.

(from text) Seven records of suspended secondary moult (S6 or S5-6) in thunbergi from the Ebro delta, 23.9 - 7.10.


Balát, F. (1960): A study of moulting in the Dipper, Cinclus cinclus (L.). Zool. Listy. 9: 257 - 264.

Barth, E. K.. (1975): Moult and taxonomy of the Herring Gull Larus argentatus and the Lesser Black-backed Gull Larus fuscus in Northwestern Europe. Ibis 117: 384 - 387.

(from text) Different authors have given varying dates for the initiation of the primary moult in the British subspecies L. f. graellsii. Ingolfsson (1970) said that the moult of the primaries in Iceland 'starts at about the same time that the first eggs are laid, in late May'. According to Stresemann (1971) the gulls on Walney Island in Lancashire start their moult in the beginning of June, while Harris (1971) says that the British birds 'commence their moult when they have large young...about the second week in July'.
The Norwegian material demonstrates that the date of initiation of primary moult in L. f. intermedius corresponds rather closely with that of L. f. graellsii, while L. f. fuscus starts about two months later. Thus the intermediate-coloured birds from South Norway again show a closer affinity with the light-coloured British subspecies than with the deepest black L. f. fuscus inhabiting northern Norway and the Baltic.

Bell, B. D. (1970): Moult of the Reed-Bunting - a preliminary analysis. Bird Study 17: 269 - 281.

The BTO moult cards for the Reed Bunting are analysed in conjunction with supplementary data from a population study of the species at Attenborough, Nottinghamshire.
Most of the records refer to the post-nuptial moult which is examined with particular reference to Newton's (1968) analysis of the moult of other buntings and finches. The moulting sequence of the adult generally follows the typical passerine pattern except for some individuals in which the completion of primary growth precedes that of some other regions. On average adults take about 60 days to moult, although there is some individual variation. There is a marked spread of 6 - 7 weeks in the onset of moult, which results from some adults breeding later in the year and delaying their moult accordingly. Males tend to terminate breeding activity earlier than females, and therefore tend to start moulting earlier. 95 % of the adults are all in moult between 11 and 23 August, and their complete moulting season extends from 24 June to 10 October, which is a longer and earlier period than that given by Witherby et al. (1943).
The extent of the partial post-juvenile moult is more variable than Witherby et al. suggest, tending to be more extensive in older birds in which the rectrices are often shed. Its season approximates that of the adults, although it may be slightly more prolonged due to delayed moulting in some birds from late broods.(...)

Bengtsson, S.-A. (1975): Timing of the moult of the Purple Sandpiper Calidris maritima in Spitsbergen. Ibis 117: 100 - 102.

(from the text) All but one of the birds had evidently begun to moult body-feathers in or before the first week of August. By mid-August most birds had assumed much of their characteristic dark winter plumages. Moult of the flight-feathers was also well advanced in August and must in many cases have started at the end of July; only two birds showed no remix moult in August. On 14-16 August all birds observed had moulted their primaries except for the last three or four.

Bensch, S., L. Gezelius, M. Grahn, D. Hasselqvist, Å. Lindström & U. Ottosson (1985): Influence of brood size on moult in female Willow Warblers. Orn. Scand. 16: 151 - 152.

Bensch, S. & M. Grahn (1993): A new method for estimating individual speed of moult. Condor 95: 305 - 315.

We introduce a new method, Residual Raggedness Value (RRV), for estimating molt duration for individual birds captured only once during a molting period. The method is developed and tested using data from Willow Warblers (Phylloscopus trochilus) in prebasic (post-nuptial) molt collected in Swedish Lapland during 1983-1990. The wing raggedness value (RV) describes the amount of "missing" feather area in the wing of a molting bird. RV was positively correlated with stage of molt. The RRVs from this correlation were used to obtain an estimate of the size of the gap in the wing that was independent of stage of molt (i.e. RV controlled for stage of molt). Molt speed of recaptured birds was highly correlated with RRV at the first capture (r2 = 0.57). Thus an individual's future molt speed could be predicted at the first capture with a high degree of accuracy. Compared to other methods for estimating molt duration, the RRV method produced estimates close to those obtained from recaptured birds. The widely used regression method for estimating molt duration (regressing date of capture on molt score) gave estimates that deviated substantially from both those obtained from the recapture and RRV methods. Our new method is a potentially powerful tool for increasing sample sizes of individual molt speeds in a studied population. This will facilitate understanding how individual birds may adjust the timing and duration of molt in relation to breeding and migration. The RRV method is probably applicable to most species that molt feathers sequentially. However, slow-molting species with few simultaneously growing feathers might be problematic.

CP: Does the molt speed really vary that much between individuals of a population, or is some particular bottleneck of Swedish Lapland involved here? I will test the method on one or two South Scanian materials where there is some doubt about the resulting regression.

Berger, W. (1967): Die Mauser des Sprossers (Luscinia luscinia L.). J. Orn. 108: 320 - 327.

(Transl.) Sequence and duration of postnuptial moult and juvenile body moult in Thrush Nightingales were investigated. The material comprised 124 moulting inds. (81 ad, 43 juv), caught and ringed on Isle of Hiddensee in 8 years. Six birds were retrapped in the same moulting period after 10 to 30 days.(...) Growing remiges had a daily growth rate of 4.2 mm. The moult starts with P1 being shed at least 5 days after young birds leaving the nest. It is finished after appr. 32 to 35 days with the completion of the new P9. The moulting period of adult Thrush Nightingales is compressed by interaction of two factors: increased growth rates and shorter intervals between shedding of remiges. According to Zeidler House Sparrows (Passer domesticus) take 79 to 82 days to complete their remige moult. Their daily growth rate of remiges is appr. 2.6 mm. Juveniles only moult body feathers and most of the wing coverts. This exchange starts when young birds leave the nest and lasts approximately 18 days.

Beser, H. J. (1972): Beitrag zur Mauser und zum "Mauserzug" des Kiebitzes. Charadrius 8: 45 - 56.

Birkhead, T. R & A. M. Taylor (1977): Moult of the Guillemot (Uria aalge L.). Ibis 119: 80 - 85.

Boddy, M. (1992): Timing of Whitethroat Sylvia communis arrival, breding and moult at a coastal site in Lincolnshire. Ring. & Migr. 13: 65 - 72.

Boere, G. C. (1976): The significance of the Dutch Waddenzee in the annual life cycle of Arctic, Subarctic and Boreal waders. Part 1. The function as a moulting area. Ardea 64: 210 - 291.

CP: Boere doesn't distinguish suspended moult from arrested moult, and gives the regression MOULT SCORE on TIME (approximating the average moult score of an individual in the population at any given time; cf Ginn (1975), J. Orn. 116: 263-280), so the numerical results stated are misleading. (Such values are quoted by Ginn & Melville (1983) in "Moult in Birds" without comment, and by Meltofte (1993) in the following way: remige moult lasts c3 months and is finished during September and October (Boere l.c.))). Still, the transparency of the paper makes it valuable; the reader can make the correct conclusions for himself. The possibility of widespread moult start on breeding grounds is dawning on Boere by this time, as it is on Gromadzka ten years later. (So what is quoted here is an incorrect conclusion when it comes to the duration of moult, and several of the internal quotes may be incorrect as well).

Nieboer (1972) and Boere et al (1973, in prep.) have shown that the birds which moult their remiges in the Dutch Waddenzee mainly belong to the subspecies Calidris alpina alpina. The mean time needed in an individual bird to complete the moult of remiges is about 87 - 94 days. This differs from the time calculated for birds belonging to other populations, e.g. C. a. schinzii moulting in Morocco and Mauritania, 60 - 70 days (Pienkowski 1972, Dick 1975, Pienkowski et al. 1976); C. a. sakhalina breeding and moulting at Point Burrow, Alaska, 65 - 70 days; C. a. pacifica moulting in the Yukon-Kuskokwim Delta in Alaska, about 97 days (Holmes 1966 a, 1966 b, 1971, Maclean & Holmes 1971).

(The following part of the discussion deserves to be quoted as well). Lilja (1969) found 20 % of the birds in Finland in arrested moult; Lessels (1974) examined 17 adult Dunlins in Northern Norway, 2 of which being in arrested and 9 in active wing moult. This shows that at least part of the birds belonging to the subspecies C. a. alpina (including C. a. centralis, if accepted), starts primary moult on or near their northern breeding grounds, or during the first part of their migration to the Waddenzee or elsewhere in Western Europe. Still I found arrested moult in only few specimens, and it is virtually impossible to detect in any moulting wing whether it had started from an arrested or non-arrested stay.

Boyd, H. & L. S. Maltby (1980): Weights and primary growth of Brent Geese Branta bernicla moulting in the Queen Elizabeth Islands, N.W.T., Canada, 1973-1975. Orn. Scand. 11: 135 - 141.

Weights of 900 Brent Geese captured at 30 siteswhile flightless are examined. The geese included representatives of two breeding stocks and some moult-immigrants. The population to which an individual belonged seemed to have less effect on its weight than did its age, sex, recent breeding effort or the site where it was moulting. The mean weights, in kg, of adult males were 1.37 ± 0.35, of adult females 1.23 ± 0.40, of yearling males 1.22 ± 0.26, and of yearling females 1.16 ± 0.28. Females that had laid tended to weigh less than non-breeders taken in the same place. Though the weather in the spring and summer of 1974 was exceptionally poor, so that no geese and there was little plant growth, moulting geese weighed as much as in late July 1974 as in the other years. The geese at a few sites weighed well above the general average. The mean weights of these moulters are only 5 - 7 % less than the annual means of a collection of published weights of other Brent Geese. Capture caused appreciable temporary loss of weight, averaging 80 g after 5 days. Measurements of the growth of the longest primary feather indicated a mean daily increment of about 6 mm/day; the geese being able to fly again before the wings are fully grown, the flightless period was no more than 22 - 25 days. Individuals with well grown new primaries weighed less than those caught at tyhe same time and not yet showing new primaries, the difference being more marked in males.

Branson, N. J. & C. D. T. Minton (1976): Moult, measurements and migrations of the Grey Plover. Bird Study 23: 257 - 266.

A study has been made of Grey Plovers Pluvialis squatarola at the Wash using ringing, population counts, measurements and moult data. The population is entirely Eurasian in origin. The recovery data confirm breeding in western Siberia, a main migration pattern through the Baltic, and wintering in Europe and west Africa. Peak numbers of up to 4,000 are present at the Wash in late summer, of which about 2,000 stay to moult. Some move south after completing wing moult, but approximately 1,500 remain for the winter, representing about 5 % of the wintering population of western Europe.(...)
Between 25 % and 40 % of adults arriving at the Wash in late summer have commenced primary moult elsewhere, and arrive in a state of arrested moult. An average duration of primary moult for the species is approximately 90 days. About 16 % of adults present in winter have not completed primary moult and remain in arrested moult until at least the following spring.

Broekhuysen, G. J. & A. R. Brown (1963): The moulting pattern of European Swallows, Hirundo rustica, wintering in the surroundings of Cape Town, South Africa. Ardea 51: 25 - 43.

1) Observations on the different age classes of European Swallows "wintering" in the neighbourhood of Cape Town, show that a high percentage of the Swallows arriving in November are birds which are two or more years old. Large numbers of birds of the year, presumably immature arrive somewhat later. By January when all birds have arrived these young birds are in majority.
2) During their stay in the winter quarters the Swallows undergo a complete moult which is a gradual process and spread over several months.Full details of the moulting pattern and its progress for the different parts of the body are given.
3) The overall moult in older birds "wintering" around Cape Town does not show a convincing difference with birds of the year which have arrived later.
It is shown that by the time the Swallows depart for their journey north, a considerable number have not fully completed the moulting process yet.
The moulting pattern of Cape Town birds is compared with birds wintering in the Congo. It was found that on the whole Congo birds were more advanced in their moult than Cape Town birds at the same periods of their stay.
6) The weight of wintering birds is compared for the different months of their stay. Some significant difference was found. Apparently no spectacular increase in weight occurs prior to departure. The importance of this lack of reserves in connection with the sensitivity to adverse climatic conditions encountered during migration is stressed.

Bub, H. (1981): Stelzen, Pieper und Würger. Kennzeichen und Mauser europäischer Singvögel. Die Neue Brehm-Bücherei 545, Ziemsen, Wittenberg Lutherstadt.

Bährmann, U. (1970): Über das Variieren der Schwanzmauser beim Star (Sturnus vulgaris L.). Beitr. Vogelkunde 15: 434 - 436.


Coooper, J. & L. G. Underhill (1991): Breeding, mass and primary moult of European Starlings Sturnus vulgaris at Dassen Island, South Africa. Ostrich 62: 1 - 7.

Coooper, J. Underhill, L. G. & G. Avery (1991): Primary moult and transequatorial migration of the Sooty Shearwater. Condor 93: 724 - 730.

Copete, J. L., L. M. Copete, J. Domenech & J. C. Senar (1992): A case of a Serin Serinus serinus with an extra secondary. Ring. & Migr. 13: 177 - 178.

Craik, J. C. A. (1994): Aspects of wing moult in the Common Tern Sterna hirundo.. Ring. & Migr. 15: 27 - 32.

In 1989 and 1990 the number of twice-moulted innermost primary feathers and the number of twice-moulted outermost secondary feathers, which together form the pale mid-wing panel in Common Terns, were recorded from birds caught during the breeding season at colonies in west Scotland. In each year, these numbers were positively correlated. The mean value of each, and of their sum, were significantly greater in 1990 than in 1989. There was no change in either number with age. There was no sexual difference in the number of twice-moulted secondaries or in the sum of twice-moulted primaries and secondaries; males had a slightly greater number of twice-moulted primaries than females in 1990 but not in 1989. It is suggested that this plumage characteristic of Common Tern may be used as an aid to species recognition, particularly in distinction from the very similar Arctic Tern S. paradisaea at long range. The date of onset of primary moult in a captive Common Tern became earlier in each of the first six years of its life.

de la Cruz Solis, C., de Lope Rebollo, F. & E. da Silva Rubio (1991): Sexual dimorphism in the post-juvenile moult in the Azure-winged Magpie Cyanopica cyanea cooki. Ring. & Migr. 12: 86 - 90.

A sexual dimorphism in the postjuvenile moult of the Azure-winged Magpie Cyanopica cyanea cooki is described. Males retain significantly fewer primaries, secondaries, upper greater primary coverts and rectrices than females. This difference is interpreted as an adaptation for mate selection and to improve reproductive success.

Curry-Lindahl, K. (1963): Molt, body weights, gonadal development and migration in Motacilla flava. Int. Orn. Congr. Ithaca 13: 960-973.

Different subspecies of the Yellow Wagtail leave the wintering grounds in tropical Africa in a certain order and without any relation to changes in local weather conditions. The first to leave in spring is the southerly race M. f. feldegg, members of M. f. lutea are next to take off, followed by M. f. flava and M. f. flavissima, while the last to leave its winter quarters is the northernmost M. f. thunbergi.
Physiological phenomena, molt, fat deposition, and gonadal development as well as departures on migration in these races (populations) of M. flava follow different patterns, in spite of the fact that the birds are wintering together in uniform external conditions.
The normal sequence of physiological events while the Yellow Wagtails are to be found in tropical Africa is approximately as follows. Molt occurs in December - April, fat deposition in January - April, gonadal growth in February - May, and spring migration also in February - May. The molt may be terminated before or after migration, while deposition of fat and initiation of growth of gonads precede the vernal flight. Prior to the onset of spring migration, the swelling gonads are still small and only slightly advanced beyond the condition that is found during the previous months. Arrival at the breeding areas occurs for different races in March - June. In M. f. flava and M. f. thunbergi the gonads increase tremendously in size during the migratory flight. Reproduction can generally start immediately after the arrival of these races at their breeding grounds.
The wide scale of temporal range in the initiation and further development of gonadal growth, with all its reproductive processes, as well as of molt and fat deposition, indicates that each subspecies depends on different internal, rhythmical factors. These may be linked with external stimuli to which the birds are exposed when they are in their breeding range, or they may involve an internal timer, which is entirely innate from the very beginning of the birds' life, thus also in this case synchronized to the conditions at the breeding grounds.


Dean, W. R. J. (1977): Moult of Little Stints in South Africa. Ardea 65: 73 - 79.

Quantitative data on the moult of Little Stints at Barberspan, South Africa, are presented. Little Stints arrive during late August and september and begin to moult during September to December. Primary moult scores have a wide range in December and January and suggest that wintering Little Stints come from different breeding areas. Mean daily increase in primary score is 0.87 ± 0.14. The estimated duration of primary moult is 100 - 115 days.
The moult of the primaries, secondaries, tail and body are synchronised and the entire moult appears to have a sigmoid pattern.
Retrap data collected at Barberspan suggest that Little Stints seldom spend the whole austral summer, or complete primary moult, at a single locality.

De Bont, A. A. (1962): Composition des bandes d'Hirondelles de cheminée Hirundo rustica rustica L. hivernant au Katanga et analyse de la mue des rémiges primaires. Gerfaut 52: 298 - 343.

The plumage and molting of the primaries were examined in more than 4,300 Swallows ringed and released in Elisabethville (Katanga) in 1955, 1956 and 1957. The first Swallows are seen in Elisabethville at the beginning of the rainy season (October), but during the first weeks they do not sleep in the roosts used by most of the hivernates, since they are on their way to spend the winter further south. The Kipopo roost, where the birds were taken, is used from December onwards, their number increasing rapidly and reaching more than 20,000. The birds leave in March or April, depending on the years. Judging by the ringed birds which were recaptured, all the birds sleeping at Kipopo sem to come from the eastern part of Europe. Although it is possible that newly-arrived birds relay those leaving for the north, this affects only a small percentage of the population. The ringed birds prove that at least some remain at Kipopo from December to March. So a hard core of local winter visitors exists.
As the season advances, the percentage of young birds in the population increases. By the time the swallows have come to the end of their stay, we can say that nearly only young birds remain. This change in population structure may be due to two factors; the arrival of a greater number of young birds, and the earlier departure for the north of some adults whose molt of the primaries is more advanced. It is only in January and February that the proportion of adults to young birds is what one can expect of a species whose annual mortality rate is 63 %. We would point out that after examining birds captured especially in the equatorial zone, Herroelen finds a greater number of adults. This leads us to suppose that at least in our part of Africa, adults do not go as far south as juveniles.(...)
The averages for the state of moult in the different months show that there is no important difference between the birds wintering in South Katanga and those examined by Herroelen. The molt of juveniles is generally later. The difference from adults varies from 5 to 6 weeks according to the year in question. At the same date there was therefore an average difference of 1.75 feather between the state of molt among juveniles and adults. The difference decreases towards the end of the swallows' stay. The molt of the juveniles is also spread out; this could be related to their very different age-groups. During the same season the state of molt of the population does not change uniformly. This is mainly due to the arrival or departure of birds in delayed or advanced state of molt.(...) We can safely say that for the adults the average gap between the shedding of two consecutive primaries must be more than 23 days and less than 25. We may add that in January we observed a bird which remained 21 days without losing its 6th old primary. There is no such uniformity among the juveniles. In some we find that a period of more than 21.5 and less than 22.5 days elapses between the shedding of two consecutive primaries; this time-span is almost the same as observed among adults. However, some juveniles show a very rapid moult; at most 17.6 days elapse between the shedding of two consecutive remiges. This would seem to be the case for young late hatched birds who start to molt later, but at a quicker rate. The state of molt among some birds in two successive years backs up this hypothesis.
The time necessary for the complete replacement of the primaries among adults and juveniles - except for those born late in the previous season of reproduction, would be about 6.5 months. We may deduce from this that many swallows therefore make part or even both their annual flights while their primaries are molting. Thus this factor would not be as serious a handicap as one might be tempted to believe. Besides, the flying activity (?, CP) during the period of reproduction in regions where food is not necessarily plentiful, is certainly not inferior to that of migration.

De Roo, A. (1966): Age-characteristics in adult and subadult Swifts, Apus a. apus L., based on interrupted and delayed wing-moult. Gerfaut 56: 113 - 134.

Age-characteristics and their dependance on the wing-moult are described in the Swift, Apus a. apus (L.).
An unshed 10th (outermost) primary is found in 30 % of adult Swifts in Europe (43 specimens examined). This primary is renewed in September and October independently of the general descendant moult-sequence which takes about six to seven months between the middle of August and the end of February (60 specimens examined, mainly from the Congo-basin).
Juveniles do not moult the primaries during their first winter in Africa (14 specimens). This moult is delayed until their second stay in Africa. Immature Swifts (i.e. yearlings) in Europe are distinguished (in the hand) from fully adult breeding birds by comparing the relative sharpness of the tips of the primaries. These feather tips are sharp-pointed and worn in the subadult age-group, blunted and unworn in adults. An unshed 10th primary gives additional evidence in three out of ten adult birds.(...)

Dhondt, A. A. (1973): Postjuvenile and postnuptial moult in a Belgian population of Great Tits, Parus major, with some data on captive birds. Gerfaut 63: 187 - 209.

Moult in Belgian Great Tits, based on 206 moulting adults and 136 juveniles captured between 1967 and 1971 is described and compared with the results presented by Flegg and Cox (1969) for the British subspecies.(...)
Postjuvenile moult is partial, invariably involving the tail and tertials. Tail moult used as the indicator for postjuvenile moult starts sooner after fledging in young from second broods than in young from first broods; when the first are about 65 days old and the latter about 75 days old. Tail moult can be finished by the end of August but can still be going on at the beginning of October. The bastard wing is renewed in about half of the birds, compared with only 8 % in a British population. More males than females and more first brood than second brood young moult the bastard wing.
Postnuptial moult starts with primary 1 but does not finish with primary 10 since secondary moult finishes about a week after primary moult. Adults with second broods start moulting about three weeks after the other adults, their lag being retained to the end of moult. Males start primary moult about a fortnight before females but tend to finish later, which indicates that the rate of female primary moult is higher. The same is found for the rate of secondary moult. No difference is found in timing of primary moult between age classes nor between years. Individual differences, however, seem to be consistent from year to year. In captive birds, primary moult progresses normally, but secondary moult is slower than in wild birds. The rate of primary moult decreases when secondary, tail, tertial and body moult start almost simultaneously. The duration of tail and tertiary moult is about the same and moult in these tracts is finished about two weeks before the end of primary moult. Variations in moult rate are observed for primaries, secondaries and rectrices. Moult is slower at the beginning and end of the progress in any tract, and slower when moult is progressing in several tracts. Differences in moult rate are not due to differences in growth rate of individual feathers but rather to differences in the interval between the shedding of successive feathers.
It is suggested that the greater dispersal of young from second broods is the result of these birds still moulting in September, being therefore at a disadvantage in competition with first brood young. It is shown that in adult males with second broods moult overlaps both with the feeding of the young and with autumn territorial behaviour. Males have a lower moult rate than females. It is suggested that this is an adaptation which makes it possible for these birds toraise two broods and take part in autumn territorial skirmishes which play an important role in the regulation of Great Tit populations.

Dhondt, A. A. (1981): Postnuptial moult of the Great Tit in southern Sweden. Orn. Scand. 12: 127 - 133.

Postnuptial moult in a Great Tit population in S. Sweden covers a period of about 4.5 months (June-October), while in an individual moult takes about 3 months. Secondary, tail and tertiary moult start about simultaneously, when P4 is growing. Tail and tertiary moult finish about two weeks before primary moult, while secondary moult continues for about two weeks after the primaries are renewed. CP: All estimates are on the high side here.
Comparing the integration of moult in the annual cycle at Lund, S. Sweden, and in Belgium, I find that at Lund adults can start moult while raising first brood young, something not observed in Belgium. In both populations males start moult before females, but in Belgium male moult is slowed down because of its overlap with autumn agonistic behaviour, so that males and females terminate moult at about the same time. There is no such overlap at Lund which results in males finishing moult before females there.
Birds finishing moult later grow shorter wings, this possibly being a 'price' for raising two broods.

Disselhorst, G. (1961): Ascendente Handschwingen-Mauser bei Muscicapa striata. J. Orn. 102: 360 - 366.

The examination of eight specimens of the palearctic Flycatcher Muscicapa striata collected in the wintering grounds in Tanganyika Territory and Kenya Colony, all in different stages of complete prenuptial moult, yielded the unexpected result of ascending primary moult (beginning with the outermost primary), in contrast to the descending mode so far known to be followed by all Passeriformes.
With regard to the moult of secondaries and tail-feathers the material, somewhat scanty in this request, seems to show that in both these feather-tracts too the ordinary Passerine sequence is reversed, the rectrices being moulted centripetally and the secondaries diverging from a single moult centre represented by the sixth (secondary), but this needs corroboration.
A superficial search among other members of the genus Muscicapa, including M. gambagae, and among other genera of Flycatchers disclosed the usual descending primary moult in all these forms.(...)

Dougall, T. W. & R. S. Craig (1997): Duration of post-juvenile moult in the Meadow Pipit Anthus pratensis. Ring. & Migr. 18: 35 - 36.

(from text)From 1993-95 five of the 1,124 birds (0.44 %) were aged as adults. Including the earlier study (...), only six of 1,619 birds (0.37 %) were probably adults, which suggests very few adults occur in the autumn population, or an age bias in tape-luring is present. During 1994 and 1995, active tail moult was found in 5.37 % of juveniles,(...). There is a suggestion that in southern Scotland, juvenile Meadow Pipits which renew some tail feathers usually moult one of the central four.

Drenckhahn, D. (1968): Die Mauser des Kampfläufers, Philomachus pugnax, in Schleswig-Holstein. Corax 2: 130 - 150.

Dwight, J. (1900): The Sequence of Plumages and Moults of the Passerine Birds of New York. Ann. N. Y. Ac. Sc., Vol. 13, No. 1.


Earnst, S. L. (1992): The timing of wing molt in tundra swans: energetic and non-energetic constraints. Condor 94: 847 - 856.

Evans, P. R., R. A. Elton & G. R. Sinclair (1967): Moult and weight changes of Redpolls, Carduelis flammea, in north Norway. Orn. Fenn. 44: 33 - 41.

Evans, P. G. H. (1986): Ecological aspects of wing moult in the European Starling Sturnus vulgaris. Ibis 128: 558 - 561.


Ferns, P. N (1978): The onset of prebasic body moult during the breeding season in some high-Arctic waders. Bull. Br. Orn. Club 98: 118 - 122.

No summary; field-work in NE Greenland, "prebasic" = postnuptial.

"None of the 11 C. alpina captured showed any trace of prebasic moult, but they were all captured close to the date when their eggs hatched. This species undergoes the whole of the prebasic moult on the breeding grounds in some regions (Holmes 1971), so it is particularly surprising that none was recorded in Greenland.

Figuerola, J. & A. Bertolero (1995): The primary moult of Curlew Sandpiper in the Ebro Delta, North-East Spain. Ring. & Migr. 16: 168 - 171.

The primary moult of Curlew Sandpiper was studied at a staging area in the south of Europe. The duration of primary moult was estimated as 73 days (9 August to 21 October), a shorter period than those reported in the wintering areas. Birds in moult showed a lower speed of fat accumulation than non-moulters. An increase in the proportion of moulting birds was detected at the end of the migratory period, probably as a result of a longer staging time of moulting birds in the study area. The number and sex-ratio of birds in wing moult showed a great annual variation. The broding system of this species, in which only females give parental care, and the great annual variation in breeding success could be two of the factors that explain the great yearly variation in the moult schedule of Curlew Sandpiper.

Flegg, J. J. M. & C. J. Cox (1969): The moult of British Blue Tit and Great Tit populations. Bird Study 16: 147 - 157.

Scatter diagrams of 'primary scores' of Blue and Great Tit moult do not form parallelograms, but are sigmoidal. It is suggested that this renders impracticable the calculation of regression lines and the estimation of mean starting and finishing dates for primary moult. If the mean dates for groups of primary scores (1-5, 6-10 etc.) are calculated, the near-linear portions (between P=10 and P=40) of the graphs derived from them may be used for comparative purposes.
Moult of the primaries in Blue Tits in Southeastern England may start in late May, before the young fledge, and has commonly started by early June. The start of moult in the Midlands and West, and in the North, is successively later. Primary moult generally finishes in August in the Southeast and between mid-August and mid-September in the Midlands and the North. It appears that the rate of primary moult is faster in the North, although the sample is small. Although tail moult is complete before the finish of primary moult, the secondaries continue to moult for several days. Body moult continues ubtil late September or early October.
Post-juvenile moult in the Blue Tit, recorded from a Kentish study population, begins on average in mid July with the wing coverts and tibia, followed by the tertials and the remaining body and head feathers. Moult is normally complete by late September, but individuals still in head moult may be found into October. Approximately 15 per cent were found to have replaced the central pair of tail feathers, and about 50 per cent replaced the bastard wing.
Moult of the primaries in Great Tit in Southeastern England, as in the Blue Tit, may start in late May whilst the young are still in the nest, and has commonly started in early June. The start of moult is just over a week later in the Midlands and West, and just over two weeks later in the North. Primary moult generally finishes between mid-August and mid-September in the Southeast, and between late August and late September in the Midlands, West and North. The rates of moult are similar in the three regions. Tail moult is completed shortly before primary moult, but secondary moult continues for several days. Most body moult finishes shortly after primary moult, but head moult may persist slightly longer.
Post-juvenile moult in the Great Tit, recorded from a Kentish study population, begins on average in the latter half of July with the tail, wing coverts and body plumage simultaneously, followed in early August by the tertials and head. At least 80 per cent of the birds examined moulted the entire tail. Head moult is usually the last to finish at the end of September. No replacement of the bastard wing was recorded, although this had occurred in 8 per cent of a Hertfordshire population.

Flinks, H. (1999): Muster, Intensität und zeitliche Aspekte der postjuvenilen Mauser beim Schwarzkehlchen (Saxicola torquata.) Vogelwarte 40: 11 - 27. (Pattern, extent and time aspects of the postjuvenile moult in stonechats).
Pattern, extent and duration of moult as well as the influence of the hatching date in first-year birds was studied in 320 stonechats from 1991 to 1996 in Nordrhine-Westfalia, Germany. The age of 60 birds could be determined exactly. 9 birds were caught twice during moult. The moult of the body feathers is most significant for the postjuvenile moult. Earliest start of moult was at July 2 (± 8 days), latest finishing at October 31 (± 12 days). Stonechats of the first brood (born between the beginning of April and mid-May) start their postjuvenile moult at an age of 68 ± 11 days, those of the second brood (born between mid-May and end of June) at an age of 46 ± 10 days, and those of the third brood (born between the beginning of July and August) at an age of 34 ± 6 days. Average duration of moult is 71.1 days in birds from first broods, 68.2 days in birds from second broods and 57.5 days in birds from third broods. Some birds from third broods start migration to their wintering grounds with active moult. (This should be more substantiated. CP). The duration of moult in retrapped birds varied between 45.5 and 79.2 days with an average of 60.1 days; this represents a progress of 1.58 moult-score points per day in body-feathers (of a total of 95 score points spread over 19 feather areas with score from 0 - 5 each.
(...) Stonechats born late during the year replace at least the greater coverts 7 to 10. The primary coverts and the primaries are moulted only exceptionally (three birds). Only 17.5 % of the birds of the first broods renew tail-feathers during the postjuvenile moult.
Partial moult of the wing feathers, tail-feathers, alula, and carpal covert was not different in males (mean = 5.6, s.d. = ± 3.7 growing feathers) and females (mean = 6.3, s.d. = ± 3.8 growing feathers). The calendar effect in the duration (for each day that hatching is later as compared to the average, the termination of moult is advanced for 0.6 days) and the pattern of moult in stonechats is compared with other species. The significance of the moult of the four innermost greater coverts (white speculum) is explained by their function as sexual and intraspecific signal.(...)


46 entries 28.5.05, links corrected 3.4.04.

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